What do banner markings primarily identify?

Banner markings primarily identify the highest overall classification level of the document or page. This marking provides immediate visibility regarding the sensitivity of the information contained within the document. By clearly displaying the classification level at the top and bottom of each page, individuals can quickly assess how to handle the document appropriately, ensuring that they adhere to security protocols.

This is crucial because knowing the overall classification assists in determining the level of access required by personnel and informs them of the potential risks associated with unauthorized disclosure. Properly marking documents helps prevent accidental exposure of sensitive information to those who do not have the necessary clearance. While other options address different aspects of document handling, they do not serve the explicit purpose of informing readers about the overall classification level, which is the primary function of banner markings.